CN112292228A

CN112292228A - Head part, welding tool and welding method

Info

Publication number: CN112292228A
Application number: CN201980039003.7A
Authority: CN
Inventors: B·里克特; S·弗勒尔克; 高军华; S·哈伯泽策尔
Original assignee: KUKA Deutschland GmbH
Current assignee: KUKA Deutschland GmbH
Priority date: 2018-06-08
Filing date: 2019-06-07
Publication date: 2021-01-29
Anticipated expiration: 2039-06-07
Also published as: DE102018113680A1; KR20210011393A; WO2019234212A1; US20210170520A1; CN112292228B; US11498153B2; KR102727736B1; EP3801972B1; EP3801972A1

Abstract

The invention relates to a head part (3) and a welding tool (1), in particular an FSW tool, equipped with the head part, and a welding method. The head part (3) has a passage opening (4) for the welding device (2) for plasticizing, in particular the rotating welding pin. The head piece ( 3 ) also has a contoured end side ( 13 ) facing the workpiece ( 7 , 8 ) during the welding operation, the end side having end side regions ( 14 , 15 ) of different heights and inclined shoulders ( 17 ) ), this shoulder guides the plasticized material of the workpiece (7, 8) and connects the end regions (14, 15).

Description

Head part, welding tool and welding method

Technical Field

The invention relates to a head part, a welding tool, in particular an FSW tool, and a welding method, in particular an FSW method, having the features specified in the preambles of the independent method and device claims.

Background

Such FSW tools and FSW methods for friction stir welding are known from practice. This friction stir welding is also known as friction-stir welding (FSW). The abbreviation FSW will be used hereinafter to represent friction stir welding.

Disclosure of Invention

The object of the invention is to propose an improved welding technique, in particular FSW technique.

The object of the invention is achieved by the features of the independent claims for the method and the device.

The claimed welding technology, in particular the FSW technology, i.e. the head part, the welding tool and the welding method and the weld resulting therefrom, have various advantages. With this welding technique, workpieces having a height difference at the weld seam, for example workpieces having a lap joint or workpieces of different thicknesses having a butt joint, which are placed one on top of the other, can be welded better and more reliably than before, in particular FSW welding.

The quality and strength of the weld can be improved. Furthermore, the gap between the workpieces can be sealed off in a sealing manner by means of, for example, an oblique welding transition region. This is particularly advantageous for the overlapping of workpieces that are placed on top of one another. Such sealed seam closure can prevent crevice corrosion or other corrosive or other adverse environmental effects. Particularly advantageous is also the possibility of: i.e. the welding of the work pieces placed on top of each other at a lap joint near the edges of the work pieces. Furthermore, the described weld transition region also contributes to the strength and the advantageous structural formation of the weld in such an edge region. Furthermore, such a sloped transition region is advantageous in terms of stress technology.

In one embodiment of the invention, a head part for a welding tool, in particular a FSW tool, is provided with a passage opening for a welding device for plasticizing, in particular a rotating welding pin, wherein the head part has a profiled end face which faces the workpiece during the welding operation, the end face having end face regions of different heights. These end regions project to a different extent beyond the end faces or end faces.

An inclined shoulder connects these end-side regions of different height and can guide the material of the workpiece plasticized by the welding device during the welding process. The inclined shoulder also compensates for the difference in height of the end side regions. The shoulder is preferably oriented transversely to the welding feed direction and has an inclined orientation or inclination corresponding to the height difference. There are many different options for the design and placement of such an inclined shoulder.

In one embodiment, the inclined shoulder is arranged in the region of the passage opening of the head part, on said end-side region and at the outlet of the passage opening there. The inclined shoulder can be arranged in the rear region of the passage opening, in particular as viewed in the welding feed direction. Accordingly, in one embodiment, the inclined shoulder may have a substantially straight extension and, if necessary, be spaced at the rear from the passage opening.

In a particularly advantageous embodiment, the inclined shoulder is curved and, in its rear region, viewed in the welding feed direction, surrounds the passage opening in a semi-annular or semicircular manner. Here, the inclined shoulder can be connected directly to the edge of the passage opening. The opening edge can at the same time be a shoulder edge.

The inclined shoulder can have a shoulder surface, in particular an arc surface, which has a raised portion

The shoulder surface or the arc surface can here be lowered from its front edge facing the passage opening toward the rear. By the raised portion, the front shoulder edgeThe rim may form a space for influencing and guiding the plasticized material during the relative movement between the head part of the welding tool and the work pieces to be welded.

In a further embodiment, end-side regions of the head part of different heights can extend in the welding feed direction starting from the passage opening. Here, they may also have a flat surface. In one embodiment, the profiled end face has two end face regions of different heights. The number of end-side regions can also be greater than two. The height difference of the end side region is related to the normal direction on the main plane of the end side of the head part. This direction may coincide with the axis of the passage opening at the outlet on the end side. By means of these end regions of different height, the head part can be laid flat on the workpiece or closely adjacent to the workpiece. This is particularly advantageous when the workpieces have different heights at the weld joint.

Straight step sections can be formed between the end-side regions of different heights. The step can start approximately centrally from the front edge of the passage opening and extend in the welding feed direction. The straight step may form a guide edge for the movement of the welding tool and its head piece during the welding feed. This simplifies and improves the precise guidance of the welding tool during the welding process and improves the welding quality. During the weld feed, the welding tool may be oriented perpendicular to the workpiece surface. Alternatively, the welding tool can also be oriented obliquely in the feed direction, wherein, for example, the tip of the welding device leads out.

The height difference of the end-side regions or the height of the straight step can be adapted to the height difference of the workpieces to be welded. Here, the workpieces can be placed on top of one another and welded with a lap joint. On the other hand, workpieces of different thicknesses may be butted and welded in a butt joint. Such adaptation may include a coincidence or approximation of the height difference.

The claimed head unit is a technically and economically independent unit. It may be arranged fixedly or detachably in the bonding tool. The head part may be present when the welding tool is first equipped. It may also be retrofitted or added to the welding tool, if desired, for example, to replace another existing head piece.

The claimed welding tool, in particular an FSW tool, has a welding device for plasticizing, in particular a rotating welding pin, and the claimed head part has a passage opening for the welding device. In contrast to the preferred embodiment as an FSW tool, the welding tool can also be designed differently and have a further welding device for plasticizing. This may be, for example, a high-energy beam, an etching needle, etc., depending on the orientation of the channel opening. The head piece may also be successfully used with other types of bonding tools.

In one embodiment, the head part is arranged on the welding tool in a rotationally fixed manner. Accordingly, in the FSW welding tool, the welding pin rotates in the head part and can also be arranged to be axially movable if necessary.

The welding tool can also have other required components, for example a drive for a rotating welding pin or other welding device for plastification, a holder for the welding device for plastification, in particular a rotating welding pin, and an interface for an operating device.

Preferably, the handling device can be a multi-axis and in particular a haptic industrial robot. Such an industrial robot preferably has four, five or more controllably driven robot axes. A haptic industrial robot may have a corresponding sensing device for registering an external load. The sensor device may be a sensor device arranged between the welding tool and a handling device, in particular a driven element of an industrial robot. In a preferred embodiment, the haptic industrial robot has an integrated sensor device. It may have a sensor on the robot shaft that registers the load. These sensors may be in particular force sensors or torque sensors. Furthermore, displacement sensors or other sensors can also be arranged on the robot axis. A welding device comprising the claimed welding tool and handling device, in particular the multi-axis haptic industrial robot, can likewise be the subject of the present invention.

The head part can be arranged on the welding tool in an exchangeable manner. Here, it can be configured as an adapter for different workpieces to be welded with varying height differences. The head part may be detachably fastened to the welding tool in a suitable manner, for example by means of a screw connection or a bayonet connection. A connection technique that enables a precise rotational orientation of the head part relative to the provided and possibly programmed welding feed direction is advantageous. The welding tool may be fitted with different head pieces or sets of adapters. This makes it possible to adapt to different workpiece and process conditions quickly and easily.

The invention also relates to a weld part made of workpieces welded by the claimed welding method, in particular the FSW method. The weld has the stated advantage that the gap initially present between the workpieces to be welded can be sealed off by the weld transition region at the weld seam. The welding transition region may preferably have an inclined design. In this way, the transition points or steps between the workpieces lying one on top of the other in the overlap joint or between the workpieces abutting one another in the abutment joint can be filled by the weld seam.

Further preferred embodiments of the invention are given in the dependent claims.

Drawings

The invention is illustrated schematically and schematically in the drawings. Wherein:

fig. 1 and 2 show a head part for a welding tool in different side views;

fig. 3 shows a cross-sectional view through the head part according to section line iii-iii of fig. 2;

FIG. 4 shows another cross-sectional view of the head member;

fig. 5 and 6 show different perspective views of the head part and its end side;

figures 7 and 8 show top and side views of the head part;

fig. 9 shows a further enlarged sectional view through the upper head part region at the end side; and

fig. 10 shows a welded lap joint between workpieces placed on top of each other with a beveled weld transition region.

Detailed Description

The invention relates to a head part (3) for a welding tool (1), in particular a FSW tool. The invention also relates to the welding tool (1), in particular to an FSW tool, and to a related welding method, in particular to an FSW method. The invention also relates to a welded part manufactured by the method.

Fig. 1 to 9 show the head part (3) in different views. The head part (3) may be a detachable component of the welding tool (1), in particular of an FSW tool. The bonding tool (1) is only schematically shown in the figures.

The welding tool (1) has, in addition to the head part (3), a welding device (2) for plasticizing the workpieces (7, 8) and further components. In the embodiment shown for friction stir welding, the welding device (2) is a schematically shown rotating welding pin which is mounted rotatably and, if necessary, also axially adjustably in a suitable holder (not shown). The further components can be a rotary drive, if necessary also a feed drive for the welding device (2), a control, etc.

The welding tool (1) can be moved and guided along a welding path by a not shown operating device in a welding feed direction (6) relative to two or more workpieces (7, 8) to be welded. The welding tool (1) can be moved relative to the stationary workpieces (7, 8). Alternatively, a kinematic reversal or a relative movement of the two parties is possible. The handling device may for example be a multi-axis industrial robot as described above, preferably a haptic industrial robot. The welding tool (1) can have a suitable interface for fastening to an operating device and, if necessary, also for supplying the required production data.

The workpieces (7, 8) can be formed, for example, as sheet metal. In fig. 10, they form, for example, vessel flanges which are welded hermetically and at least corrosion-resistant to the outside. In fig. 1 to 3, for example, tailor-welded blanks are shown.

Various welding arrangements of workpieces (7, 8) and weld joints (9) are shown in the figures. Fig. 1 to 3 show a butt joint between the end sides of workpieces (7, 8) of different thicknesses. Fig. 10 shows a lap joint of two workpieces (7, 8) placed on top of each other. In both variants, a step is formed between the thick or upper workpiece (8) and the thin or lower workpiece (7).

The welding device (2) is directed at the joint or weld joint (9) of the workpieces (7, 8). Which loads two workpieces (7, 8) on their respective edges, for example as shown in fig. 1 and 10. In this case, different tool coverings can be produced, for example, wherein the coverage on a thick or upper workpiece (8) is greater.

The workpieces (7, 8) can be made of the same or different materials, in particular of metal. In the example shown, they are each made, for example, of a light metal alloy (e.g., an aluminum alloy). Alternatively, it may be a pair of materials that are melted or plasticized differently, such as light metal alloys and steels.

The head part (3) shown in the figures has a preferably central passage opening (4) for the welding device (2) and an end face (13) or end face which faces the workpieces (7, 8) during the welding operation. The passage opening (4) opens at the end face (13). The head piece (3) may, for example, have the shape of a hollow body, which is shown in the sectional views of fig. 3 and 4, and may be detachably connected to the components of the welding tool (1) by means of a screw connection, a plug-in or bayonet connection, or in another suitable manner. Alternatively, a permanently fixed connection is also possible.

The welding tool (1) and the head part (3) are in the drawing oriented perpendicularly to or in the direction of the normal to the main plane or surface of the workpieces (7, 8) to be welded. Likewise, the passage opening (4) has such an orientation with its central axis (5). The axis (5) may also be the central axis of the head part (3). The axis (5) is oriented perpendicularly to the welding feed direction (6).

In a variant of the illustrated embodiment, the welding tool (1) and the head piece (3) can be oriented relative to the workpieces (7, 8) at a slight inclination relative to the welding feed direction (6) and at a so-called penetration angle of, for example, about 2 ° relative to the normal direction. The tip of the welding device (2) acting on the workpieces (7, 8) and on the weld joint (9) can be brought out in the welding feed direction (6).

The head part (3) has a profiled end face (13) with end face regions (14, 15) of different heights. The end regions (14, 15) project to a different extent from the end face (13) or from the main plane thereof. These end-side regions (14, 15) have the height differences (h) shown in fig. 3 and 8. The height difference (h) can be oriented in the direction of the axis (5).

The head part (3) has an inclined shoulder (17) which connects the end-side regions (14, 15) of different heights. The shoulder (17) compensates for the height difference and guides the material of the workpiece which is plasticized during the welding process. As a result, the weld transition region between the workpieces (7, 8) shown in fig. 10 can be formed on the weld seam (11).

The welding device (2) is applied earlier and, if necessary, more strongly to the thick or upper workpiece (8), whereby the material thereof is plasticized and extruded more. The step between the workpieces (7, 8) is thus filled by the guided plasticized material and the welding transition region (12). The welding transition region (12) can have an inclined extent.

In another variant of the lap joint, in which the workpieces (7, 8) lie flush on top of one another, the weld transition region can be formed in another way, for example in the form of a cap.

By means of the welding transition region (12), it is possible to seal off the gap (10) (see fig. 10) existing between the workpieces (7, 8) to be welded.

As shown in fig. 1 to 9, an inclined shoulder (17) is arranged in the region of the passage opening (4). It is located in the rear region of the passage opening (4) as seen in the welding feed direction (6). In the exemplary embodiment shown, the inclined shoulder (17) is curved and surrounds the passage opening (4) in a semi-annular manner in the rear region of the passage opening (4) or, in the case of a circular passage opening (4), in a semi-annular manner around the passage opening (4).

In the embodiment shown, the inclined shoulder (17) has a surface or curved face (18). The width of which can remain constant along the arc angle. The curved shoulder (17) is directly connected to the passage opening (4) on the rear side, as seen in the welding feed direction (6), wherein the edge (19) of the shoulder (17) or of the curved surface (18) thereof is at the same time the opening edge.

The arcuate face (18) may have a rise. The elevation here descends backwards starting from its front edge (19). The edge (19) is here the part of the arc-shaped surface (18) that protrudes furthest in the direction of the axis (5).

In a variant that is not shown, the inclined shoulder (17) can be spaced apart from the passage opening (4) counter to the welding feed direction (6). In addition, it can also have a different, for example straight, extent and can be oriented transversely to the welding feed direction (6). Here, it can maintain its said inclined arrangement or position to guide the plasticized material.

End side regions (14, 15) of different heights can start from the passage opening (4) and extend in the welding feed direction (6). They preferably each have a flat surface. Fig. 4 to 7 show such a design.

The upper end-side region (14) is connected flush at the height of the axis (5) to the upper end of the shoulder (17) or the curved surface (17). At the lower connecting point of the shoulder (17) or the curved surface (18), a recess (20) can be present on the lower end-side region (14).

Between the end side regions (14, 15) of different heights, for example, a straight step portion (16) is formed. According to fig. 5 to 6, the step starts approximately centrally from the front edge of the passage opening (4) and extends in the welding feed direction (6).

According to fig. 4, 5 and 9, the surfaces of the end-side regions (14, 15) can be oriented obliquely to one another, viewed transversely to the feed direction (6). The inclination can in this case, for example, each decrease in the direction of the step (16). It is also possible to orient the surface of the lower end-side region (15) at right angles to the normal direction or to the axis (5), while the surface of the upper end-side region (14) is inclined in the manner described. These surfaces may also be oriented parallel to each other.

The head part (3) may have an obliquely descending cutting section (21) on the upper side. Thereby, the end side regions (14, 15) and the inclined shoulder (17) which mainly co-act with the workpieces (7, 8) can be exposed, and constraints during welding feed can be avoided. The head part (3) may have a preferably cylindrical body on a front region facing the workpieces (7, 8). The end-side regions (14, 15) end at the body edge in the feed direction (6).

The height difference (h) of the end-side regions (14, 15) is formed on the step (16). The step wall extends, for example, perpendicularly to the surface of the end-side region (14, 15) and can extend parallel to the axis (5).

The height difference (h) of the end-side regions (14, 15) can be adapted to the height difference (w) on the workpieces (7, 8) to be welded. According to fig. 1 and 3, in the case of butt joint, this height difference (w) can be present on workpieces (7, 8) of different thicknesses. On the other hand, according to fig. 10, for workpieces (7, 8) lying one above the other, this height difference can be present at the overlap joint.

In the case of the adaptation, the height difference (h) may be as large as the height difference (w). Alternatively, it may be close to and slightly smaller than the height difference (w). For example, it is the case that the welding tool (1) and its axis (5) are oriented obliquely with respect to the penetration angle of the workpieces (7, 8). In this way, a defined better contact of the head part (3) with only one end-side region (14, 15), in particular the lower end-side region (15), can also be achieved on the upper or higher workpiece (8). Furthermore, jamming between the workpieces (7, 8) is prevented.

The head member (22) may also have one or more openings (22) extending inwardly from the housing to the passage opening (4). They can be used, for example, for discharging plasticized material sucked in from the passage opening (4).

The opening (22) may have a substantially circular access opening on the edge of the passage opening (4). On the outside of the head part (3) or its body, the access opening may be larger. Which may extend for example a distance in the circumferential direction of the body. This is advantageous for rotary discharge. The orientation can be oblique to the axis (5) or in the form of a screw segment. The openings (22) can be present on both sides on the head part (3) and can open opposite one another on the passage opening (4).

In the exemplary embodiment shown, the head part (3) is arranged on the welding tool (1) in a rotationally fixed manner. The head part (3) can be arranged exchangeably on the welding tool (1) by means of a screw connection, a bayonet connection or the like. The head part (3) can be designed as an adapter for different workpieces (7, 8) to be welded with varying height differences (w). The end regions (14, 15) of different head parts (3) can have different height differences (h).

During welding, the welding tool (1) can be guided with the head part (3) over the weld joint (9) in the feed direction (6). The step (16) between the end regions (14, 15) can serve as a guide edge. It can be pressed against the end face of a thicker workpiece (8) in the butt joint or against the end face of an upper workpiece (8) in the overlap joint. This guide contact can be detected by the operating device with suitable force measurement and used to control or regulate the feed movement.

The welding tool (1) can be fed to the workpieces to be welded from the upper side of the workpieces to be welded (7, 8) at the beginning of the welding process in a vertical or inclined feed movement. By means of a rotating welding pin (2), for example, a starting hole can be formed by plasticizing the workpiece material and then a welding feed (6) can be carried out. During the feed, the head part (3) can be oriented in a suitable manner with respect to the feed direction (6) and the weld joint (9). The head part (3) can be coupled to the actuating device in a rotationally fixed manner by means of a welding tool (1) and has a known rotational assignment.

The welding device (2) is schematically shown in the drawing. It can be designed as a rotating welding pin with a suitable workpiece plasticizing effect for FSW welding tools, for example as a conical tip. In other embodiments, the welding device (2) can be designed differently and can plasticize the workpieces (7, 8) at the welding point.

Variations of the illustrated embodiment may be implemented in different ways. The number and arrangement of the end-side regions (14, 15) of different heights can be varied, in particular if more than two workpieces (7, 8) are to be welded.

List of reference numerals

1 welding tool, FSW tool

2 welding device, welding pin

3-head unit, adapter

4 channel opening

5 axes of rotation

6 welding feed direction

7 workpiece

8 workpiece

9 welded joint, lap joint, butt joint

10 gap

11 welding seam

12 welding the transition region

13 end side

14 end side region of the projection

15 sunken end side region

16 step part, guide edge

17 inclined shoulder

18 arc-shaped surface

19 edge

20 recess

21 cutting part

22 opening

height difference of h end side region

w height difference of the workpiece.

Claims

1. A head part for a welding tool (1), in particular a FSW tool, having a passage opening (4) for a plasticized welding device (2), in particular a rotating welding pin, wherein the head part (3) has an end side (13) which faces a workpiece (7, 8) during a welding operation, characterized in that the head part (3) has a profiled end side (13) which has end side regions (14, 15) of different heights, wherein an inclined shoulder (17) for guiding the plasticized material of the workpiece (7, 8) connects the end side regions (14, 15).

2. Head piece according to claim 1, characterized in that the inclined shoulder (17) is arranged in the rear region of the passage opening (4) in the region of the passage opening (4), in particular as seen in the welding feed direction (6).

3. Head piece according to claim 2, characterized in that the inclined shoulder (17) is configured arc-shaped and surrounds the passage opening (4) in the area of its rear part in a semi-annular manner.

4. Head piece according to claim 1, 2 or 3, characterized in that the arc-shaped face (18) of the inclined shoulder (17) has a rise and descends backwards starting from its front edge (19) facing the passage opening (4).

5. Head piece according to any one of the preceding claims, characterized in that the end side regions (14, 15) of different heights extend from the passage opening (4) in the welding feed direction (6) and preferably have a flat surface.

6. Head piece according to any one of the preceding claims, characterized in that a straight step (16) is constructed between the end side regions (14, 15) of different heights, which step extends approximately centrally in the welding feed direction (6) starting from the front edge of the passage opening (4).

7. Head piece according to any one of the preceding claims, characterized in that the height difference (h) of the end side regions (14, 15) is adapted to the height difference (w) of the workpieces (7, 8) to be welded on the weld joint (9), in particular to the height difference (w) of the workpieces (7, 8) lying one above the other on an overlap joint.

8. Welding tool, in particular FSW tool, having a welding device (2), in particular a rotating welding pin, for plasticizing and having a head part (3) with a passage opening (4) for the welding device (2), characterized in that the head part (3) is constructed according to at least one of claims 1 to 7.

9. Welding tool according to claim 8, characterized in that the head piece (3) is arranged on the welding tool (1) rotationally fixed.

10. Welding tool according to claim 8 or 9, characterized in that the head piece (3) is exchangeably arranged on the welding tool (1) and is designed as an adapter for different workpieces (7, 8) to be welded having varying height differences (w) over the welding joint (9), in particular a lap joint.

11. Welding method, in particular FSW method, for welding workpieces (7, 8) with a welding tool (1), in particular a FSW tool, which is guided along a welding path by a multi-axis, preferably tactile, industrial robot, characterized in that the welding tool (1) is constructed according to at least one of claims 8 to 10.

12. Welding method according to claim 11, characterized in that the workpieces (7, 8) are welded at the edge region with a height difference (w) on the weld joint (9), in particular on the lap joint.

13. Welding method according to claim 11 or 12, characterized in that the plasticized material is guided with the head part (3) of the welding tool (1) during the welding process, wherein a preferably oblique welding transition region (12) is formed between the workpieces (7, 8) at the weld seam (11).

14. Welding method according to claim 11, 12 or 13, characterized in that the welding tool (1) is guided along the weld joint (9) by means of a step (16) of the head piece (3) during welding.

15. Welding method according to any one of claims 11-14, characterized in that during welding, the gap (10) between the work pieces (7, 8) is sealingly closed.

16. A weld part made of workpieces (7, 8) which are welded by means of a welding method, in particular an FSW method, characterized in that the workpieces (7, 8) are welded by means of a welding method according to at least one of claims 11 to 15, wherein a gap (10) between the workpieces (7, 8) is sealingly closed on a weld seam (11) by a preferably inclined welding transition region (12).